/*
 * (C) Copyright 2011-2016 Nuxeo SA (http://nuxeo.com/) and others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Contributors:
 *     matic
 */
package org.nuxeo.runtime.management.jvm;

import java.io.File;
import java.io.IOException;
import java.lang.management.ManagementFactory;

import javax.management.MBeanServer;

import org.nuxeo.runtime.api.Framework;

import com.sun.management.HotSpotDiagnosticMXBean;

/**
 * Helper to dump the heap in a temporary file.
 *
 * @author matic
 * @since 5.5
 */
public class HeapDumper {

    private static final String HOTSPOT_NAME = "com.sun.management:type=HotSpotDiagnostic";

    public HeapDumper() throws IOException {
    }

    protected final HotSpotDiagnosticMXBean diag = newDiag();

    protected HotSpotDiagnosticMXBean newDiag() throws IOException {
        MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
        return ManagementFactory.newPlatformMXBeanProxy(mbs, HOTSPOT_NAME, HotSpotDiagnosticMXBean.class);
    }

    /**
     * Dumps heap in a temporary file and returns the file
     *
     * @since 5.5
     * @throws IOException
     */
    public File dumpHeap() throws IOException {
        File file = Framework.createTempFile("heapdump", ".hprof");
        file.delete();
        newDiag().dumpHeap(file.getAbsolutePath(), true);
        return file;
    }

}
